For a concise description of the current situation with XEmacs, see this message from the Cygwin mailing list: 'http://cygwin.com/ml/cygwin/2002-11/msg00609.html'.

You can't use the same copy of Gnus in both as the Lisp files are byte-compiled to a format which is different depending on which Emacs did the compilation. Get one copy of Gnus for Emacs and one for XEmacs.

XEmacs versions 21.4.* are releases made from the current stable sources. XEmacs versions 21.5.* (which will be released as 22.0) are releases made from the development sources. Check at http://www.xemacs.org for the current minor version. XEmacs versions 21.1.* were the previous stable releases, now retired. XEmacs 19.16, released in November, 1997. was the last release of v19, and was also the last version without international language support.

XEmacs is the result of the time and effort of many people, and the active developers have changed over time. There are two major components of the XEmacs effort -- writing the code itself and providing all the support work (testing the code, releasing beta and final versions, handling patches, reading bug reports, maintaining the web site, managing the mailing lists, etc. etc.). Neither component would work without the other.

XEmacs 21.5 (perhaps 21.4 also?) works on MacOS X, although it certainly will not feel very much like a Mac application as it has no Mac-specific code in it. There is also a port of XEmacs 19.14 that works on all recent versions of MacOS, from 8.1 through MacOS X, by Pitts Jarvis (recently deceased). It runs in an equivalent of TTY mode only (one single Macintosh window, 25 colors), but has a large number of Mac-specific additions. It's available at http://homepage.mac.com/pjarvis/xemacs.html.

Carl Edman, apparently no longer at cedman@princeton.edu, did the port of GNU Emacs to NeXTstep and expressed interest in doing the XEmacs port, but never went any farther.

VMS has never been supported by XEmacs. In fact, all the old VMS code inherited from GNU Emacs has been removed. Sorry, all you VMS fans out there.

It depends on the knowledge and time you possess. If you are able, by all means become a beta tester (see section Q1.5.2: How do I become a beta tester?). If you are a programmer, try to build XEmacs and see if you can improve it. Otherwise, you can still help by using XEmacs as your everyday editor (for pre-built binary versions, see section Q1.1.2: Are binaries available?) and reporting bugs you find to the mailing list.

First, get yourself set up under CVS so that you can access the CVS repositories containing the XEmacs sources and the XEmacs packages. Next, set up your layout. This is important, as a good layout will facilitate getting things done efficiently, while a bad layout will could lead to disaster, as you can't figure out which code is the most recent, which can be thrown away, etc.

RMS has asserted at times that XEmacs is merely a "patch" on top of GNU Emacs (see section Q1.6.4: Is XEmacs "GNU"?). In fact, probably not more than 5% of the code, if that, remains unchanged, and nearly 14 years of work has gone into XEmacs at this point. (GNU Emacs itself is only than 20 years old, and thus XEmacs has existed as a separate product for over 2/3 of the lifespan of GNU Emacs.) As a point of comparison, XEmacs 21.

XEmacs is GNU software because it's a modified version of a GNU program. And it is GNU software because the FSF is the copyright holder for most of it, and therefore the legal responsibility for protecting its free status falls on us whether we want it or not. This is why the term "GNU XEmacs" is legitimate. In fact, FSF is not the copyright holder for most of the code, as very little unmodified FSF code remains (see section Q1.6.3: How much does XEmacs differ?).

You need to manually select and install either the "MULE-free" (fw_xemacs.latin1.eoe) or "MULE-fied" (fw_xemacs.mule.eoe) subsystem, depending on how much foreign language support you want. When installing xemacs click on the "Customize" button in the software manager, and click on the little folder icon next to XEmacs product. Select the subsystem you want and hit "Start". This message will appear whenever you try to use DB_File or GDBM_File in perl5.6.1 (package version 1277898120).

See the file 'etc/NEWS' for information on new features and other user-visible changes since the last version of XEmacs. The file 'INSTALL' in the top-level directory says how to bring up XEmacs on Unix and Cygwin, once you have loaded the entire subtree of this directory. See section Q2.1.1: How do I install the packages?, for the installation of (essential) add on packages.

XEmacs will run in place without requiring installation and copying of the Lisp directories, and without having to specify a special build-time flag. It's the copying of the Lisp directories that requires so much space. XEmacs is largely written in Lisp. You will obviously use whatever directory you downloaded the source tree to instead of '/src/xemacs-21.5'). The space required by the installation directories can be reduced dramatically if desired. Gzip all the .el files.

Because of the way XEmacs (and every other Emacsen, AFAIK) is built. The link gives you a bare-boned emacs (called temacs). temacs is then run, preloading some of the lisp files. The result is then dumped into a new executable, named xemacs, which will contain all of the preloaded lisp functions and data. Now, during the dump itself, the executable (code+data+symbols) is written on disk using a special unexec() function. This function is obviously heavily system dependent.

It can be a lot easier to edit long pages using your favorite editor from your favorite web browser. Mine is Emacs (or sometimes its cousin XEmacs) and Firefox (http://www.mozilla.org/products/firefox/), and I have assembled instructions from other places that I was able to get working on my How_to_use_XEmacs_for_wiki_edits page.

Learning XEmacs is a lifelong activity. Even people who have used Emacs for years keep discovering new features. Therefore this document cannot be complete. Instead it is aimed at the person who is either considering XEmacs for their own use, or has just obtained it and is wondering what to do next. It is also useful as a reference to available resources.